This proposal is fundamentally directed toward investigations of the vertebrate retina which may elucidate: (1) functional neuronal networks of the retina and their role in the visual process; (2) The specific relationship between intracellular (neural as well as glial) and extracellular potentials so that the electroretinogram and other retinal potentials may be unequivocally interpreted; and (3) the interactions between neurons and glia, including any specific cases which may affect retinal information processing, or which generate significant field-potentials.